Headboard



FIG. 1 is a left front perpsective view of a headboard showing my new design;

FIG. 2 is a side elevational view, the opposite side being a mirror image thereof; and,

FIG. 3 is a front elevational view thereof.

The bottom and rear views of the headboard are not shown and form no part of the claimed design. 

The ornamental design for a headboard, as shown and described. 